Comments on: Greenwich prime meridian

By: Tom Drennan

Tom Drennan — Tue, 19 Aug 2008 18:57:54 +0000

Three items if you please:

1. - I can understand people having different ideas about where to place the 0.00 E/W point on the face of the Earth.

New Orleans is at 90 W by 30 N. Easy to remember and easy to visualize on a globe. For fifty plus years I’ve used the location as my prime map point to locate other places in North America estimating time and distance. It has served me well. I wouldn’t recommend it as candidate for relocating the prime meridian but it is a handy reference point.

2. - Where on the map is Greenwich? Almost every map of Western Europe shows the Greenwich Mean Line. Most information about the observatory includes the fact the place is in England Many websites show pictures of the observatory. I’ve been surfing the web looking for more than an hour and I haven’t found a map that shows a point for the place. That seems odd when it has to be one of the most important places on Earth for map makers.

Is it in the London area, north, south or a mythical location like Shingra La? I saw the movie so there are pictures but no maps.

3. - It seems to me, some people don’t have enough to do when they want to fix something that isn’t broken, like the Prime Meridian. When a thing works so well for so long let it be. Maybe they should use that time trying to fix something that needs help. There is a wide range of projects open to them from unwanted weeds that pop in lawns to the world wide energy crunch.

That’s right, I’m bored so I’m picking on you.

Thank your for your indulgence and courtesy. Tom.

By: Barry

Barry — Thu, 06 Dec 2007 23:43:21 +0000

Another good reason to keep the Greenwich Meridian is the international date line. I believe it was one of the decieding factors in the international agreement to use Greenwich in the beginning, when we went from a meridian in every capital city to just one. The International date line runs roughly along 180 degrees, with a few kinks to go around islands so that generally land masses and island groups are on the same date.

The current location of the date line is one of the only places it can be and not pass through any major land mass north to south. So Greenwich is actually a very logical place to have the meridian on the other side of the world.

Wikipedia - International Date Line

By: ajho

ajho — Mon, 03 Dec 2007 02:09:53 +0000

Hmm. Looks like the good burgers of Peacehaven were a little out when the built their Prime Meridian Obelisk at Placemark: Google Maps / Google Earth

By: Timhogs

Timhogs — Fri, 30 Nov 2007 19:31:35 +0000

I was trying to think of a way to account for tectonic drift on a global scale, but then I decided that mrb had the right idea all along. Barkeep, more brandy!

By: Izzy

Izzy — Fri, 30 Nov 2007 14:54:12 +0000

I would put it through the Royal Observatory in Edinburgh.

You know what really annoys me about time zones? That the French are always one hour ahead of the UK even though they’re on the same longitude pretty much.

By: Jel

Jel — Fri, 30 Nov 2007 11:26:47 +0000

Further to my last (bedevilled by an aberrant cup!), the supposedly inconsequentlial field a hundred meters east of the Meridian centre is actually quite important in the recent history of the Marathon, as it is there that the local kids, inspired by the fundraising of the adults in the London Marathon which starts on the avenue alongside, held a fund-raising jog in 1984, which was taken up by the local schools the next year and then became the Mini Marathon phase of the London Marathon, which in its turn has inspired a number of imitations elsewhere. I know, ‘cos I organised that first jog!

By: Jel

Jel — Fri, 30 Nov 2007 11:17:49 +0000

The old esoteric arguments worked off a form of omphalos concept, that each city had is own prime meridian defined by its own gnomon, a founding stone, which in London’s case has shifted around a bit but is currently enshrined in the wall of a bank opposite Cannon Street Station.
The reason the UK meridian is Greenwich was a combination of the Tudor Royal Palace at the foot of the hill (which is accidentally better located for the modern zero) and the three geographic promontories of the bowl of hills surrounding London which overlook the Thames, which are Blackheath Point, the Observatory, and St Luke’s, Charlton.
For all that you s
Of these, the first faces the City and is not much use for shipping, the last was comandeered by the church so long ago the astronomers never got a look in, which only left the Observatory site itself.
The reason it was needed on high ground was to provide maximum visibiity for the captains of departing ships, who would delay setting the timepieces their navigation depended on until the absolutely last instant possible, to keep as much accuracy as could be gained. Each day, a massive ball drops on a pole on the roof, indicating noon for this reason.
Blackheath Point is in itself interesting as it’s the closest vantage point overlooking London itself, and so has seen a number of invaders set up there, from Julius Caesar to Wat Tyler and Jack Cade, both of whom were revolting peasants at various times.

By: Flümo

Flümo — Fri, 30 Nov 2007 09:52:32 +0000

Peter: Actually, it would be rather easy

How do you define “height”?
ASL? Farthest away from the Earth’s centre? Highest monotonically increasing slope?

All those would yield different results, and I’m sure there still are other possibilities.

By: fred

fred — Fri, 30 Nov 2007 08:37:51 +0000

I’d put the Meridian through the place on the earth where it would cross the most land. Maybe that’s down the middle of Africa? It would be cool to be able to visit the point where the Meridian crosses the Equator (currently in the sea somewhere?).

By: Peter

Peter — Fri, 30 Nov 2007 03:30:42 +0000

How about the meridian through the tip of Mount Everest. The highest point on earth would be difficult to argue over.